Fireplace construction and damper therefor



Sept. 26, 1933.

N. MULCAHY 1,928,499 FIREPLACE CONSTRUCTION AND DAMPER THEREFOR Filed oct. 2e, 193i 2 sheets-sheet 1 IN VEN TOR.

/VE/L MU/ cAA/ K A TTORNEYS.

N. MULCAHY Sept. 26, 1933.

FIREPLACE CONSTRUCTION AND FER K'IHERE'FOR 1931 24 Sheets-Sheet 2 Filed Oct. 26

INVENTOR. /Vf/L MaL c4 fr A T TORNEYS.

ma? Q Patented Sept. k26, i933 IREPLACE 4CONSTRUCTI'ON AND DER THEREFR Neil Mulcahy, San Francisco, Calif.

Application (lctcber 26, 1931. Serial No. 571,191

1 claim.

.The present invention relatesv to replace constructions and dampers therefor, and has particular reference to a damper adapted to be incorporated in a fireplace of novel design, during the building of the latter.

An object of my invention is to provide a damper ofthe character described that may be utilized for controlling the draft in the flue or" the fireplace andthe amount of heat deflected into the surrounding room. The gate forming part of the damper is arranged to be swung step by step through successive small arcs -ofv opening, and I make use of novel means for retaining the gate in the different stages of opening.

A further object is to provide means for opening and closing the gatey of the damper with facility and ease, and which will require the minimum of effort on the 'partofj the operator.

A still further object resides inthe shaping ofthe fireplace flue in such a manner as to pre- K Figure lis a fragmentary side elevation of av fireplace embodying my invention with parts shown in central transverse section;

Figure 2 is a i'ace view of the operating cam looking toward the right in Figure 1;

Figures 3 and 4 are perspective views of the damper frame and the gate, respectively;

Figure 5 is a plan view or" the assembled damper; and i Figure 6 is a front elevation of the same.

In carrying my invention into practice, I provide a fireplace generally indicated at 1, and having a combustion chamber 2 formed therein, a curved rear wall or back 3 shaped for deflecting heat under the conventional arch 4 into the room facing the lireplace, and a flue 5 for carrying away the products of combustion.

Particularly it will be noted from Figurefl that the 'iue includes a horizontally arranged passageway 6 that is offset relative to the vertical passageway 7. A down draft in the'flue will accordingly be turned in its course toward the inner front wall 8 defining part of the flue. The energy of the draft will be practically spent before the air finds its way into the combustion chamber, which communicates withthel passageway 6 through a damper 9, hereinafter described. Thus the tendency of the fireplace tosmoke is materially reduced. Y Y

, For supporting the course of ybrick orother refractory materiali() Yoverlying the passageway 6, I provide a hood 1l, one end of; which rests on a horizontally-mounted angle bar or the like 12, while the opposite end is abutted `against the wall 8 in the manner illustrated.

The damper as previously mentioned includes a damper frame 13 of substantially rectangular shape, having a free passageway extending therethrough, and provided with'a marginal flange 14 projecting outwardly from the bottom of the frame and adapted for introduction into the brick work during the building of the replace. This frame is preferably arranged with its upper end in registry with the bottom 15 of the passageway 6, and the rear wall 16 of the frame is inclined so as to conform with the general slope of the back 3 of the fireplace.

The damper action of controlling the draft in the ilue is accomplished by a gate 17 having trunnions 18, one of which is adapted to be introduced through an opening 19 in the end 20 of the damper frame, and the opposite trunnion then Y being insertable into a bayonet slot 21 in the opposite end 22. The gate, when in lowered position, forms a closure over the discharge 23 of the frame and thus the major portion of the heat from the combustion chamber is directed into the room facing the arch 4.

Means for swinging the gate 17 step by step through successive small degrees of opening takes the form in the present disclosure of a cam 24 fashioned by bending the operating rod 25 intermediate of its length. The cam takes the general shape of' a gradually increasing spiral when looking from the front of the iireplace (see Figure 3) I the cam also being made spiral in side elevation. The rod 25 is journalled in the damper frame,v and may be rotated by a crank 26 or other suitable means conveniently operated from a position in front of the replace. f

The cam is shaped so that its leading point 27, which contacts with the gate when the latter is fully closed, and initially starts the opening ofv the gate, is positioned at a considerable distance from the axis of the trunnions 18, and this allows CII the entire opening of the gate due to the lengthwise spiralling of the cam as clearly illustrated in Figure 1. The end 29 of the spiral supports the gate when the latter is moved into the dotted line position shown in Figure l.

The gate is held in any one of several raised positions by means of a polygonal member 30 xed to the rod 25 and bearing against lugs 31 on the damper frame. In this connection, it should be noted that the rod carrying Ythe cam is mounted with freedom of slight vertical movement for allowing the vertices of the polygon to move over the lugs upon turning of the crank 26.

It should be further noted that the edge 32 of the gate bears against the rod 25 and thus the sides of the polygonal member contacting with the lugs are at al1 times urged against the latter for holding the cam in adjusted position. A recess 33 in the damper frame forms the front `iournal for the rod 25, while a suitable aperture 34 serves as the rear bearing or support.

Having thus described the various parts of the device, the operation thereof may be readily understood. Assuming that the gate is lowered into closure-forming position with the damper frame 13, it is apparent that the cam 24 is so constructed thatit will gradually swing the gate toward open position by merely turning the crank 2G in a clockwise direction. The polygonal member 30 holds the cam in the desired adjusted p0- sition. Upon reversing the cam, the gate is gently lowered by its own weight into closure forming relation with the damper frame.

The cam, since it is formed from a rod, offers little resistance to the passageway of smoke from thek combustion chamber into the ue thereabove.

Although I have shown and described only one form of my invention, it should be understood that various changes or modifications may be made Within the scope of the appended claim without departing from the spirit of the invention.

I claim:

l A damper comprising a frame having a passageway leading therethrough, a gate swingably mounted relative to the passageway, a spiralshaped cam revolubly mounted in the frame and bearable against the gate, a rod for revolving the cam, arpolygonal member attached to the rod, and stationary lugs contacting with the polygonal member for holding the cam in adjusted position said rod being free to move vertically a limited distance for permitting the member to be rotated past the lugs.

NEIL MULCAHY. 

